Device for trapping solids and liquids in tobacco smoke



United States Patent Leonard L. Thomas 14092 Ash, Westminster, Calif. 92683 [21] AppLNo. 753,962

[72] Inventor [22]. Filed Aug. 20, 1968 [45] Patented Dec.22, 1970 [54] DEVICE FOR TRAPPING SOLIDS AND LIQUIDS IN TOBACCOSMOKE 4 Claims, 4 Drawing Figs.

[52] U.S.Cl. 13l/l0.5, 131/210 [51] int." ..A24d01/04 [50] FieldoISearch 131/10.5, 210,201,261B

[56] References Cited UNITED STATES PATENTS 2,728,346 12/1955 Crawford 131/10.5 2,954,787 10/1960 Lebert 131/10.5X 3,318,312 5/1967 CurtisJr... 13l/210X 3,335,733 8/1967 Brooks 13l/10.5X FOREIGN PATENTS 436,432 10/1935 GreatBritain 131/210 Primary Examiner-Samuel Koren Assistant Examiner-James H. Czerwonky Attorney-Harvey C. Nienow ABSTRACT: An apparatus for extracting liquid and solid constituents from tobacco smoke. The extraction device comprises a one-piece impedance means including a series of barriers of paper circles formed integrally as a single blank which is folded in a substantially W-shape and mounted within the smokers end of a cigarette. The first upstream barrier of this series is provided with an opening and the second downstream barrier is formed so that the flow path jacent the interior wall of the cigarette wrapper. The impedance means includes an additional barrier downstream from the first and second barriers and spaced a clear distance by several times than the distance between the first and second barriers. The additional barrier includes flow openings of greater area than the combined area of the first barrier opening and the second barrier flow path. The space between the second barrier and the additional barrier has a volume several times that of the space between the first and second barriers.

PATENTED 05022 I975 Has a 4/ n6 0 0 w a Q 0 50 mm", 4 a "MF'Q a 3 0 e 0 xi 0 a O O w FIGA ' INVENTOR.

ZEONARD l. THOMAS I a? 3 a firm/aver DEVICE FOR TRAPPING SOLIDS AND LIQUIDS IN TOBACCO SMOKE This invention relates toapparatus for extracting liquid and solid constituents from tobacco smoke and it relates particularly to apparatus for trapping tars and nicotine bearing liquids and semisolids from the smoke of tobacco from cigarettes and cigars and pipes.

An object of the invention is to provide an effective apparatus for eliminating the heavier and sticky solid liquid materials from tobacco smoke, which apparatus can be produced in a size which will fit within the end of a cigarette or pipe stem or cigar and which will operate effectively at the smoke flow rates and inhalation suction pressures which have heretofore characterized cigarette, cigar and pipe smoking.

Another object of the invention is to provide such a solid and liquid extraction device which is capable of production at a costv sufficiently .low to permit installation in tobacco products the remains of which are thrown away after use.

Another object of the inventionjs to provide a smoke solid and liquid constituent extractor or trap which is easily produced and readily installed in the end of a cigarette wrapper or paper.

Another object is to provide such a trap in aform which, by itself, can have no deleterious efi'ect upon auser.

These and other objects and advantages of the invention which will hereinafter appear are realized in part by the provision of a trap for the solid components in smoke which includes means defining a flow path for the smoke and by the provision of impedance means in the flow path for offering greater impedance to flow of liquid'and solid material along the path than is offered to gaseous and vaporous material including a means for altering the direction and velocity of the material flowing along the path as anincident to pressure differential applied across the ends of the path.

While the invention has broader application in that it can be employed with pipes and cigars and other forms of tobacco and apparatus for smoking tobacco, it is particularly advantageously employed in cigarettes. Accordingly, the embodiment of the invention selected for illustration in the drawings; and which comprises the best mode applicant has devised for practicing the invention, isa modification suitable for, and incorporated in, a cigarette.

In the drawings: l

FIG. 1 is an isometric, cross section taken lengthwise of a partially burned cigarette which incorporates a trap and embodies the invention;

FIG. 2 is a view in side elevation of the trap of FIG. 1 shown separated from the cigarette but having the configuration and shape that is has when installed within the cigarette;

FIG. 3 is a top plan view of the trap structure of FIGS. 1 and 2 prior to being formed in final shape in a cigarette; and

FIG. 4 is a top plan view of an alternative trap configuration prior to being formed for insertion within a cigarette.

Referring to FIG. 1 of the drawing, there is shown an extractor for separating solids and liquids out of tobacco smoke comprising means defining a flow path for the smoke. That means may comprise the shank end bit of a pipe, the outer wrapping leaf of a cigar, a tubular extension of the cigar, or any of a wide variety of other shapes and materials and structures including a tubular extension, at the end of a cigarette, of the cigarette paper or an overlying material.

Advantageously, as shown in FIG. 1, the flow path is formed by an extension of the cigarette at that end which is inserted in the smokers mouth. The paper tube is advantageously strengthened and maintained by a wrapper 12 of supporting material such, for example, as paper or cork. The body of shredded tobacco l4 ends short of the end 16 of the unit to provide a space in which the extractor impedance meansis disposed.

The invention incorporates impedance means in the flow path for offering greater impedance to the flow of liquid and solid materials along the path that is ofiered to gaseous and vaporous materials. This impedance means .includes a means for altering the direction and velocity of material flowing along the path as an incident to pressure differential across the ends of the path. Smoke is forced along the flow path as a result of the pressure differential so that kinetic energy is added to the several constituents of the smoke. That kinetic energy has a magnitude which is a function of the velocity squared of the constituent and its weight. The mass of the different constituents is a function of the density and volume of the various discrete bodies of those constituents. The discrete body or particle is the molecule in the case of the gases contained-in the smoke. The solid particles, while minute, may various shapes and sizes while the liquids and 'semisolids occur as minute droplets. I i

The particle or discrete unit of solids and liquid material is heavier than the gas module. Accordingly, and further because kinetic energy is a function of velocity squared, the kinetic energy of the solid and liquid materials will exceed that of the gases during initial acceleration over very short distances but asthe distance become greater the kinetic energy of the gases will exceed that of the solid and liquid particles. If the velocity and direction of the smoke is changed as the smoke proceeds down the flow path these differences in kinetic energy can be utilized to separate out the solid and liquid materials. The problem of separation by kinetic energy is complicated by the fact that the kinetic energy of the gases and particularly the vapors will exceed that of the smaller particles and droplets if the acceleration distance is made long enough to add significant energy to the solids and liquids to permit use of kinetic energy in separation. The problem may be solved in part by utilizing turbulance to dissipate the kinetic energy of the gases and vapors to a level below that of the solids and liquids.

The smoke is made to accelerate along the flow path in the direction of a surface which is capable of entrapping or retaining the solids and liquids when they impinge upon that surface. The flow path must extend beyond that surface so that the gaseous and vaporous components may proceed down the path, but the trap and the surface are arranged so that the smoke must alter its direction and flow in a direction in which its kinetic energy is less than the kinetic energy of the solid particles at the surface, or just adjacent to the surface, where the liquids and solids are being trapped.

Advantageously the impedance means, which includes a means for altering the direction and velocity of material flow along the path, comprises a maze by which the smoke is forced to change direction. In addition to the maze action, means are provided for utilizing venturi effect as the smoke proceeds through the maze to insure velocity change and specifically to insure velocity increase.

A preferred form of this means is illustrated in the drawings. It comprises at least one pair of barrierswhich extends entirely across the flow path and which are formed to permit the passage of smoke. The smoke passes through an opening or cutout in the barrier and the cutouts of the two barriers are offset in the sense that the flow opening in the second barrier is offset from the line of movement of smoke through the opening or perforation in the upstream barrier. The embodiments selected for illustration in the drawing comprise two sets of such barriersso that there are four barriers in all. The barriers are formed so that smoke passes through the central portion of two of them and around the outer periphery of the other two. They are alternated in one embodiment so that the path of smoke extends axially of the flow path and then at its outer margins and then axially again and finally the smoke flows from the trap along the outer margins of the flow path. In another embodiment the path of smoke is axial past the first and fourth barriers and is adjacent the margins of the flow path past the second and third barriers. The flow area past the barriers varies in successive barriers. Advantageously as shown, the first barrier an outside diameter that fits snugly within the inside diameter of the flow path and has a flow passage opening extending through the barrier at or near its center. The first or upstream barrier is identified in FIG. I of the drawing by the reference numeral 18 and its central opening is designated by the numeral 20. The barrier 18 is placed immediately behind the; body of shredded tobacco 14 and serves not only to confine the flow of smoke to the central opening 20 but to keep the body of tobacco 14 properly compacted and away from the rearward end 16 of the cigarette. The area of the opening 20 is advantageously between 0.002 and 0.003 square inches in area. An opening of this size offers sufficient resistance to flow so that the velocity of smoke and its constituents is increased substantially as the smoke flows through the hole. Nonetheless, the opening is sufficiently large so that only a comfortable amount of inhalation suction is required to draw smoke through the cigarette.

The barrier immediately downstream from the barrier 18 is designated by the reference number 22. It has no central opening but its diameter or width dimension is less than that of the inside diameter of the cigarette so that a space is provided between the inner wall of the cigarette paper and the outer margins of the barrier 22 through which smoke and its constituents may freely pass. The area of this space is substantially greater than the area of the opening 2050f barrier 18. As smoke is drawn through the opening 20, it is accelerated in a direction towards the central portion of the downstream barrier22. The kinetic energy of the gaseous and vaporous constituents is quickly lostin turbulence beyond the barrier 18 and to this end the barrier 22 is positioned rather close to the opening 20 so that the turbulence is substantial. Nonetheless the barrier 22 must be sufiiciently far from barrier 18 to permit the gas and vapor constituents to move slowly toward the margins of barrier 22 without applying substantial lateral forces to deflect the solid and liquid constituents from impingingupon the surface of the barrier 22. The spacing is not critical, a sufficient change in velocity can be assured by making the flow path past barrier 22 large in proportion to the area of opening 20. Advantageously, the area of the flow path past the downstream barrier is at least five times the area of the opening 20. This disparity of area accounts in part for the fact that barrier spacing is not critical and this lack of criticality permits a simplified construction in which the two barriers are integrally formed of a single piece of sheet material so that they are joined over a short arc of their outer peripheries and are 'folded, V-shaped, in the flow path with each barrier forming one arm of the V. The diameter of cigarettes is about nine-sixteenths of an inch. The diameter of the second barrier is one thirty-second of an inchless than the inside diameter of cigarettes in one successful embodiment and it was spaced so that its central region was one thirty-second of an inch behind the center of the first barrier.

In theembodiment selected for illustration in FIG. 1 there are two pairs of barriers which are alike with the exception that thecentral opening 24 of the downstream barrier 26 of the downstream set of barriers is slightly larger than the opening 20 of the upstream set of barriers. The other barrier 28 of the rear set has smaller diameter than the inside diameter of the flow path whereby to form a flow space between its outer periphery and the inner wall of the cigarette. At its right most end, in FIG. 3, the trap device is provided with a rightward extension 30 whichmay be bent over and inserted into slot 31 of barrier 28 as shown such that it serves as an aid to retaining the device in place within the end of the cigarette. The rearmost set of barriers is also bent into a V-shape, being bent at the juncture 32 between the two barriers just as the upstream set of barriers 18 and 22 is bent at the juncture 34 between them. In the preferred form of the invention the two sets of barriers are formed integrally by being connected by a connecting member or section 36 which extends from an edge of the barrier 22 to an edge of the barrier 26. The section 36 has a lengthapproximatingthe radius of the barriers so that the second set of barriers is displaced rearwardly of the upstream set of barriers. The result of this construction is shown in FIGS. 1 and 2 where the flow impedance element is shown in the folded form it has in assembled position. The connecting section 36 being relatively long, a substantial space is provided between the barriers 22 and 28. This volume, when added to the volume between barriers 26 and 28 and between barriers foration 20 in the forward area. This arrangement means that there is a substantial volume of smoke available to the smoker when first he applies suction at each inhalation. Smoke is easily withdrawn from the space between barriers 26 and 28. The required suction pressure almost immediately increases when the smoke in the space betweenbarriers 22 and 26 is drawn through the opening 24 and it is increased again when this smokein this space is depleted and smoke is drawn from between barriers 18 and 22. In practice .one of these spaces is not completely depleted before smokebegins flowing from the. next space and the netresult is thatinhalation suction is ini-v tially quite easy and becomes progressively slightly more dif-' ficult as inhalation continues. Smoke is withdrawn from the cigarette immediately to provide a sensation approximating that when no trap is employed. Once inhalation has begun the fact that a higher suction pressure is required is less discemible.

It is not essential that this. feature be provided and the How impedance device of FIG. 4 has noelongate section corresponding to 36 between the upstream and the downstream pair of barriers. Instead, the connection section 38 between barriers 40 and 42 is similar to the connecting section 44 between the barrier 40 and the upstream barrier 46 and the connecting section 48 of thebarrier42 and the downstream barrier 50. The unit of FIG. 4 also differs from that of FIG. 3 in that the downstream barrier of each pair of barriers has an outside diameter so that its outer margin fits snugly within the inside diameter of the cigarette flow path. Flowpast these barriers 40 and 50 is permitted through a series of perforations (52 in the case of barrier 40 and 54 in the case of barrier 50), which ring the outer marginal area of these two barriers. The

opening 56 of barrier 46 and the opening 58 of barrier 42 are similar to the corresponding openings-20 and 24 of the unit shown in FIG. 3 except that the opening 58 occurs in the third barrier of FIG. 4 whereasopening 24 is formed in the fourth barrier of FIG. 3.

Both the unit shown in FIG. 3 and the unit shown in FIG. 4, and other structures which provide a similar function and which will occur to those skilled in the art, are effective to cause impingement of the liquid and solid constituents of smoke upon the surfaces of the downstream barriers, 22 in FIG. 3 and 40 and 50 in FIG. 4. To a lesser extent the configuration shown in FIG. 3 results in impingement of solid and liquid materials againstthe sidewalls of the flow path as the smoke proceeds past the outer periphery of the barriers 22 and 28. The liquid constituents will adhere to almost any surface upon which they impinge. The semisolids will adhere to many surfaces but the solid materials may not adhere if the surface upon which they impinge is too smooth or is otherwise incapable of retaining them. Accordingly, in the preferred form of the invention, the barriers and other surfaces on which the solids and liquids impinge, are formed of a material which will retain them readily. Unglazed paper with its fibrous SUI-.-

face is very effective in retaining liquids and solids. Paper is im expensive, is easily formed and easily folded, and makes an excellent material both for theimpedance structure itself and fon. the inner wall of the flow path. In the preferred form the inner. wall of the flow path comprises an extension of the cigarettepaper 10 and the barrier structure comprises a heavy lightly,

colandered chipboard or cardboard material.

It has been found that only one set of barriers is needed to. remove most of the solid and liquid constituents. The trap whose blank is shown in FIG. 3 removes additional quantities. of these constituents as they are deposited on the inner wall of the flowpath. The blank of FIG. 4 is arranged to permit flow v past barrier 40 so that less of the solids and liquids are deposited on the wall but this configuration provides greater support against crushing and distortion of the cigarette wall.

The efi'ectivity of the FIG. 4 trap is increased to correspond with that of the FIG. 1 and 3 trap by reversing the orderof the last two barriers so that two traps in series are provided.

Proper spacing of the barriers 18 and 22 in FIG. 3 is aided by a tab 60 at the left which is bent over to serve as a stop against barrier 22. A similar tab or stop 62 is shown at the right end of the blank in FIG. 4. Of course other stop means may be employed and the paper block 64, which is glued to the face (the rear face) of barrier 46, is one advantageously employed example.

Although I have shown and described certain specific embodiments of my invention, I am fully aware that many modifications thereof are possible. My invention, therefore, is not to be restricted except insofar as is necessitated by the prior art and by the spirit of the invention.

I claim:

1. An extractor for disposition at the outlet end of a cigarette to remove solids and liquids from the smoke comprising, in combination:

a tube of size to serve as an extension of a cigarette;

a one-piece impedance means in said tube for offering greater impedance to flow of liquid and solid material therealong than is offered to gaseous and vaporous material by altering the direction and the velocity of material flowing through the tube as an incident to pressure differential impressed across the ends of the tube, said means comprising an upstream barrier extending across the interior of said tube and having dimensions relative to the tube to preclude passage of smoke therearound and having an opening, said impedance means further comprising a downstream barrier extending across the interior of said tube and defining a flowpath for smoke at its marginal regions adjacent said tube, the flowpath having cross-sectional area exceeding that of said opening in the upstream barrier in which said impedance means comprises an additional barrier downstream from said upstream and downstream barriers spaced a clear distance greater by several times than the distance between said upstream and downstream barriers, said additional barrier including flow openings of greater area than the combined area of said opening and said flowpath and constituting a means offering less impedance to the flow of smoke than does the combination of said upstream and downstream barriers; and

the space between said downstream barrier and said additional barrier having a volume several times that of the space between said upstream and downstream barriers serving as a storage area for smoke.

2. An extractor for disposition at the outlet end of a cigarette to remove solids and liquids from the smoke comprising, in combination:

a tube of size to serve as an extension of a cigarette;

a one-piece impedance means in said tube for offering greater impedance to flow of liquid and solid material therealong than is 'ofiered to gaseous and vaporous material by altering the direction and the velocity of material flowing through the tube as an incident to pressure differential impressed across the ends of the tube, said means comprising an upstream barrier extending across the interior of said tubeand having dimensions relative to the tube to preclude passage of smoke therearound and having a central opening, said impedance means further comprising a downstream barrier extending across the interior of said tube and defining a flowpath for smoke at its marginal regions adjacent said tube, the flowpath having cross-sectional area at least five times that of said opening in the upstream barrier and said downstream barrier being formed of paper;

in which said impedance means comprises an additional barrier downstream from said upstream and downstream barriers spaced a clear distance greater by several times than the distance between said upstream and downstream barriers, said additional barrier including flow openings of greater area than the combined area of said central opening and said flowpath and constituting a means offering less impedance to the flow of smoke than does the combination of said upstream and downstream barriers;

and the space between said downstream barrier and said additional barrier having a volume several times that of the space between said upstream and downstream barriers serving as a storage area for smoke.

3. The invention defined in claim 2 in which said upstream and downstream barriers comprise circular disclike members and are integrally formed substantially as circles from a flat sheet of paper so that they are joined at a common point along their margins and are assembled in said tube in the form of a V the apex of which is that common point, and which further comprises means for holding them in V-shape with their central regions spaced approximately one thirty-second of an inch apart.

4. The invention defined in claim 3 in which said additional barrier comprises two barrier elements, integrally formed with 

